Numerical simulation and optimization of CsPbI3-based perovskite solar cell to enhance the power conversion efficiency

In this study, we investigated the potential of CsPbI3 as an absorber material to be used in perovskite solar cells (PSCs). To optimize the device, we used TiO2 as the electron transport layer and copper barium thiostannate (CBTS) as the hole transport layer in the CsPbI3-based PSC, and employed SCAPS-1D software. We initially tested 10 different back metal contacts (BMCs) to identify the most suitable one for the primary device. After optimization of the BMC, the best-optimized device structure, ITO/TiO2/CsPbI3/CBTS/Ni, achieved a power conversion efficiency of 17.91%. We then evaluated the impact of the absorber thickness, acceptor density, and defect density on the device performance. We also analyzed the effect of changing the thickness, charge-carrier density, and defect density of the CsPbI3, TiO2, and CBTS layers, as well as the interfacial defect densities at the CBTS/CsPbI3 and CsPbI3/TiO2 interfaces, to further optimize device performance. This resulted in an improved efficiency of 19.06% for the ITO/TiO2/CsPbI3/CBTS/Ni device with HTL, compared to 18.17% without HTL. We also analyzed the impacts of operating temperature, series resistance, and shunt resistance on the final optimized device performance, as well as its capacitance–voltage, generation and recombination rate, current density–voltage (J–V), and quantum efficiency (QE) features. The results of these simulations provide valuable insights for the experimental fabrication of an efficient CsPbI3-based inorganic PSC.